Biological Bone Micro Grinding Temperature Field under Nanoparticle Jet Mist Cooling

Clinical neurosurgeons used micro grinding to remove bone tissues, and drip irrigation-type normal saline (NS) is used with low cooling efficiency. Osteonecrosis and irreversible thermal neural injury caused by excessively high grinding temperature are bottleneck problems in neurosurgery and have severely restricted the application of micro grinding in surgical procedures. Therefore, a nanoparticle jet mist cooling (NJMC) bio-bone micro grinding process is put forward in this chapter. The nanofluid convective heat transfer mechanism in the micro grinding zone is investigated, and heat transfer enhancement mechanism of solid nanoparticles and heat distribution mechanism in the micro grinding zone are revealed. On this basis, a temperature field model of NJMC bio-bone micro grinding is established. An experimental platform of NJMC bio-bone micro grinding is constructed, and bone micro grinding force and temperatures at different measuring points on the bone surface are measured. The results indicated that the model error of temperature field is 6.7%, theoretical analysis basically accorded with experimental results, thus certifying the correctness of the dynamic temperature field in NJMC bio-bone micro grinding

Soil respiration responses to soil physiochemical properties in urban different green-lands: A case study in Hefei, China

Soil respiration (RS) is an important carbon budget in urban ecosystem. In order to better understand the limiting factors affecting urban soil respiration, we measured RS, soil temperature, soil moisture content, soil organic carbon (SOC), nitrogen (N), C/N, dissolved organic carbon (DOC), microbial biomass carbon (MBC), NO3−-N, NH4+-N, P and fine root biomass from twelve sites of four green-land types (campus green-land, park green-land, residential green-land and factory green-land) for two years in built-up areas of Hefei, China. The results showed that average annual RS was significantly lower in the residential green-land (1.35 μmol m−2 s−1) than in the campus (2.64 μmol m−2 s−1) and park (2.51 μmol m−2 s−1) green-lands. RS positively increased with soil temperature at the range of 2.01–31.26 °C, and Q10 values ranged from 1.48 to 1.65 in the four types of green-lands. Soil moisture (18–25%) showed significantly positive correlation with soil respiration (P<0.01). When precipitation occurred frequently in wet summer, soil moisture served as the dominant control on RS variations. RS was positively related with SOC, NO3−-N, P and fine root biomass (diameter <2 mm), while negatively correlated with DOC at 0–10 cm depth. Our results indicate that decreasing RS may be an optional way to increase carbon sequestration potential for urban ecosystem, and this can be achieved by regulating green-land types and applying appropriate soil nutrients maintenance practices

Remote Sensing Index for Mapping Canola Flowers Using MODIS Data

Mapping and tracing the changes in canola planting areas and yields in China are of great significance for macro-policy regulation and national food security. The bright yellow flower is a distinctive feature of canola, compared to other crops, and is also an important factor in predicting canola yield. Thus, yellowness indices were previously used to detect the canola flower using aerial imagery or median-resolution satellite data like Sentinel-2. However, it remains challenging to map the canola planting area and to trace long-term canola yields in China due to the wide areal extent of cultivation, different flowering periods in different locations and years, and the lack of high spatial resolution data within a long-term period. In this study, a novel canola index, called the enhanced area yellowness index (EAYI), for mapping canola flowers and based on Moderate Resolution Imaging Spectroradiometer (MODIS) time-series data, was developed. There are two improvements in the EAYI compared with previous studies. First, a method for estimating flowering period, based on geolocation and normalized difference vegetation index (NDVI) time-series, was established, to estimate the flowering period at each place in each year. Second, the EAYI enhances the weak flower signal in coarse pixels by combining the peak of yellowness index time-series and the valley of NDVI time-series during the estimated flowering period. With the proposed EAYI, canola flowering was mapped in five typical canola planting areas in China, during 2003-2017. Three different canola indices proposed previously, the normalized difference yellowness index (NDYI), ratio yellowness index (RYI) and Ashourloo canola index (Ashourloo CI), were also calculated for a comparison. Validation using the samples interpreted through higher resolution images demonstrated that the EAYI is better correlated with the reference canola coverage with R2 ranged from 0.31 to 0.70, compared to the previous indices with R2 ranged from 0.02 to 0.43. Compared with census canola yield data, the total EAYI was well correlated with actual yield in Jingmen, Yili and Hulun Buir, and well correlated with meteorological yields in all five study areas. In contrast, previous canola indices show a very low or even a negative correlation with both actual and meteorological yields. These results indicate that the EAYI is a potential index for mapping and tracing the change in canola areas, or yields, with MODIS data

Enhanced paramagnetism of mesoscopic graphdiyne by doping with nitrogen

Abstract The new two-dimensional graphitic material, graphdiyne, has attracted great interest recently due to the superior intrinsic semiconductor properties. Here we investigate the magnetism of pure graphdiyne material and find it demonstrating a remarkable paramagnetic characteristic, which can be attributed to the appearance of special sp-hybridized carbon atoms. On this basis, we further introduce nitrogen with 5.29% N/C ratio into graphdiyne followed by simply annealing in a dopant source and realize a twofold enhancement of saturation moment at 2 K. Associate with the density of states calculation, we investigate the influence of the nitrogen atom doping sites on paramagnetism, and further reveal the important role of doped nitrogen atom on benzene ring in improving local magnetic moment. These results can not only help us deeply understand the intrinsic magnetism of graphdiyne, but also open an efficient way to improve magnetism of graphdiyne by hetero atom doping, like nitrogen doping, which may promote the potential application of graphdiyne in spintronics

Relationship between tumor size and the percentage of MDSCs or G-MDSCs.

<p>BALB/c mice were irradiated with 3 Gy, and Meth-A cells were then subcutaneously inoculated into the right flank of these mice. The percentages of MDSCs (A) and G-MDSCs (B) in the peripheral blood were then analyzed.</p

Gr-1 Ab administered after allo-BMT+TT was more effective in suppressing tumor growth.

<p>Recipient BALB/c mice with tumors were irradiated with 7 Gy one day before BMT. The next day, these mice were injected with 1×10⁷ B6 BMCs using the IBM-BMT method. For TT and Gr-1 groups, one newborn thymus was simultaneously transplanted under the renal capsule in the recipients that had received BMT. From Day 5, recipient mice in the Gr-1 and TT groups were injected with 5 ug Gr-1 or its isotype Ab respectively every other day. The tumor diameter was measured every 2 or 3 days. *<i>p</i><0.05, **<i>p</i><0.01.</p

Effects of Allogeneic Hematopoietic Stem Cell Transplantation Plus Thymus Transplantation on Malignant Tumors: Comparison Between Fetal, Newborn, and Adult Mice

We have recently shown that allogeneic intrabone marrow–bone marrow transplantation + adult thymus transplantation (TT) is effective for hosts with malignant tumors. However, since thymic and hematopoietic cell functions differ with age, the most effective age for such intervention needed to be determined. We performed hematopoietic stem cell transplantation (HSCT) using the intrabone marrow method with or without TT from fetal, newborn, and adult B6 mice (H-2b) into BALB/c mice (H-2d) bearing Meth-A sarcoma (H-2d). The mice treated with all types of HSCT + TT showed more pronounced regression and longer survival than those treated with HSCT alone in all age groups. Those treated with HSCT + TT showed increased numbers of CD4+ and CD8+ T cells but decreased numbers of Gr-1/Mac-1 myeloid suppressor cells and decreased percentages of FoxP3 cells in CD4+ T cells, compared with those treated with HSCT alone. In all mice, those treated with fetal liver cell (as fetal HSCs) transplantation + fetal TT or with newborn liver cell (as newborn HSCs) transplantation (NLT) + newborn TT (NTT) showed the most regression, and the latter showed the longest survival. The number of Gr-1/Mac-1 cells was the lowest, whereas the percentage of CD62L−CD44+ effector memory T cells and the production of interferon γ (IFN-γ) were highest in the mice treated with NLT + NTT. These findings indicate that, at any age, HSCT + TT is more effective against cancer than HSCT alone and that NLT + NTT is most effective

Temperature field model in surface grinding: a comparative assessment

Grinding is a crucial process in machining workpieces because it plays a vital role in achieving the desired precision and surface quality. However, a significant technical challenge in grinding is the potential increase in temperature due to high specific energy, which can lead to surface thermal damage. Therefore, ensuring control over the surface integrity of workpieces during grinding becomes a critical concern. This necessitates the development of temperature field models that consider various parameters, such as workpiece materials, grinding wheels, grinding parameters, cooling methods, and media, to guide industrial production. This study thoroughly analyzes and summarizes grinding temperature field models. First, the theory of the grinding temperature field is investigated, classifying it into traditional models based on a continuous belt heat source and those based on a discrete heat source, depending on whether the heat source is uniform and continuous. Through this examination, a more accurate grinding temperature model that closely aligns with practical grinding conditions is derived. Subsequently, various grinding thermal models are summarized, including models for the heat source distribution, energy distribution proportional coefficient, and convective heat transfer coefficient. Through comprehensive research, the most widely recognized, utilized, and accurate model for each category is identified. The application of these grinding thermal models is reviewed, shedding light on the governing laws that dictate the influence of the heat source distribution, heat distribution, and convective heat transfer in the grinding arc zone on the grinding temperature field. Finally, considering the current issues in the field of grinding temperature, potential future research directions are proposed. The aim of this study is to provide theoretical guidance and technical support for predicting workpiece temperature and improving surface integrity